Lily Platt is the daughter of David and Kylie Platt and half-sister of Max Turner. When Lily was born, Kylie did not know if the biological father was her husband David, or his half-brother Nick Tilsley.
Before Lily's birth, David had found out that Nick and Kylie had slept together, meaning that Nick could possibly be her father. This led David to start a hate campaign against Nick which culminated in in a car crash caused indirectly by David. After Lily was born in August 2013, Nick blackmailed David into getting a DNA test done, threatening to reveal otherwise how David was responsible for the car accident which led to Nick being in a coma for several weeks. The DNA test confirmed that David was indeed the father.
On 16th October - the day of Lily's christening, Kylie learned that David was responsible for the accident which had left Nick with brain damage and confronted him about his involvement during the church service. All the secrets of the past few months spilled out, resulting in Kylie denying David any access to Max and Lily. However later that year, David's family slowly started letting him spend time with his daughter. In January 2014, when Kylie fell asleep drunk alone with Max and Lily, David was forced to intervene. After the incident, David and Kylie fully reconciled.
In July 2016, just one month shy of her third birthday, Lily lost her mother after Kylie was stabbed to death by fifteen-year-old thug Clayton Hibbs. In October, David planned to kill himself and Clayton by driving a petrol-doused car into a police van with Clayton inside. He left a suicide video for Lily and Max explaining his actions. When David was about to put his plan into action, Lily wandered away from her babysitter Fiz Stape into the middle of the road. David saw Lily and unsuccessfully swerved to avoid her, with Gary Windass grabbing her in an attempt to take her to safety. David's car flipped and trapped Lily and Gary, but with the help of the local community, they were both rescued unharmed. David was horrified that he was nearly responsible for the death of his own daughter.
- Lily was played by twins Ava & Lilly Bushell from her birth in August 2013 until August 2014. From September 2014 until May 2016, she was played by Betsie & Emmie Taylor. The role was once again recast and taken over by Brooke Malonie the following month.
- Lily was uncredited until 3rd October 2016.